They're still in Oakland where they've played the majority of their games since 1971 (prior to that time they were known as the San Francisco Warriors after their move from Philly). So yes, the SF doesn't really make a great deal of sense, but the New York Giants and the New York Jets are still playing in New Jersey and use "NY".

Their decision was largely based on response of their 'Throwback on the Hardwood' (or whatever it was called) series, where they wore their throwback 'The City' jerseys. Fan response was unprecedented and they sold mountains of the throwback gear, so it just made sense to update it as their main. A sort of modernized throwback, not unlike what the Chargers did with their powder blue uniforms.

A little bleh, but I'm no authority on NBA uniforms either. At least it's clean.

Definitely an homage to the old "The City" uniforms of the '70s, which were awesome. The Warriors had great uniforms for a long time, until the switch to the ugly dark blue-and-orange lightning-bolt look. Warrior fans probably will look back on those uniforms like Piston fans do for the teal era.